Turn Function.prototype.bind into a hydrogen stub optimized for the common case

src/bootstrapper.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/bootstrapper.h"
 
 #include "src/accessors.h"
 #include "src/api-natives.h"
 #include "src/code-stubs.h"
 #include "src/extensions/externalize-string-extension.h"
@@ skipping 450 matching lines @@
 void Genesis::SetFunctionInstanceDescriptor(Handle<Map> map,
                                             FunctionMode function_mode) {
   int size = IsFunctionModeWithPrototype(function_mode) ? 5 : 4;
   Map::EnsureDescriptorSlack(map, size);
 
   PropertyAttributes ro_attribs =
       static_cast<PropertyAttributes>(DONT_ENUM | DONT_DELETE | READ_ONLY);
   PropertyAttributes roc_attribs =
       static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY);
 
+  STATIC_ASSERT(JSFunction::kLengthDescriptorIndex == 0);
   Handle<AccessorInfo> length =
       Accessors::FunctionLengthInfo(isolate(), roc_attribs);
   {  // Add length.
     AccessorConstantDescriptor d(Handle<Name>(Name::cast(length->name())),
                                  length, roc_attribs);
     map->AppendDescriptor(&d);
   }
+
+  STATIC_ASSERT(JSFunction::kNameDescriptorIndex == 1);
   Handle<AccessorInfo> name =
       Accessors::FunctionNameInfo(isolate(), ro_attribs);
   {  // Add name.
     AccessorConstantDescriptor d(Handle<Name>(Name::cast(name->name())), name,
                                  roc_attribs);
     map->AppendDescriptor(&d);
   }
   Handle<AccessorInfo> args =
       Accessors::FunctionArgumentsInfo(isolate(), ro_attribs);
   {  // Add arguments.
@@ skipping 134 matching lines @@
   PropertyAttributes rw_attribs =
       static_cast<PropertyAttributes>(DONT_ENUM | DONT_DELETE);
   PropertyAttributes ro_attribs =
       static_cast<PropertyAttributes>(DONT_ENUM | DONT_DELETE | READ_ONLY);
   PropertyAttributes roc_attribs =
       static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY);
 
   DCHECK(function_mode == FUNCTION_WITH_WRITEABLE_PROTOTYPE ||
          function_mode == FUNCTION_WITH_READONLY_PROTOTYPE ||
          function_mode == FUNCTION_WITHOUT_PROTOTYPE);
+  STATIC_ASSERT(JSFunction::kLengthDescriptorIndex == 0);
   {  // Add length.
     Handle<AccessorInfo> length =
         Accessors::FunctionLengthInfo(isolate(), roc_attribs);
-    AccessorConstantDescriptor d(Handle<Name>(Name::cast(length->name())),
-                                 length, roc_attribs);
+    AccessorConstantDescriptor d(handle(Name::cast(length->name())), length,
+                                 roc_attribs);
     map->AppendDescriptor(&d);
   }
+
+  STATIC_ASSERT(JSFunction::kNameDescriptorIndex == 1);
   {  // Add name.
     Handle<AccessorInfo> name =
         Accessors::FunctionNameInfo(isolate(), roc_attribs);
-    AccessorConstantDescriptor d(Handle<Name>(Name::cast(name->name())), name,
+    AccessorConstantDescriptor d(handle(Name::cast(name->name())), name,
                                  roc_attribs);
     map->AppendDescriptor(&d);
   }
   if (IsFunctionModeWithPrototype(function_mode)) {
     // Add prototype.
     PropertyAttributes attribs =
         function_mode == FUNCTION_WITH_WRITEABLE_PROTOTYPE ? rw_attribs
                                                            : ro_attribs;
     Handle<AccessorInfo> prototype =
         Accessors::FunctionPrototypeInfo(isolate(), attribs);
@@ skipping 523 matching lines @@
     function_fun->shared()->DontAdaptArguments();
     function_fun->shared()->set_construct_stub(
         *isolate->builtins()->FunctionConstructor());
     function_fun->shared()->set_length(1);
     InstallWithIntrinsicDefaultProto(isolate, function_fun,
                                      Context::FUNCTION_FUNCTION_INDEX);
 
     // Setup the methods on the %FunctionPrototype%.
     SimpleInstallFunction(prototype, factory->apply_string(),
                           Builtins::kFunctionPrototypeApply, 2, false);
-    SimpleInstallFunction(prototype, factory->bind_string(),
-                          Builtins::kFunctionPrototypeBind, 1, false);
+
+    FastFunctionBindStub bind_stub(isolate);
+    Handle<JSFunction> bind_function = factory->NewFunctionWithoutPrototype(
+        factory->bind_string(), bind_stub.GetCode(), false);
+    bind_function->shared()->DontAdaptArguments();
+    bind_function->shared()->set_length(1);
+    InstallFunction(prototype, bind_function, factory->bind_string(),
+                    DONT_ENUM);
+
     SimpleInstallFunction(prototype, factory->call_string(),
                           Builtins::kFunctionPrototypeCall, 1, false);
     SimpleInstallFunction(prototype, factory->toString_string(),
                           Builtins::kFunctionPrototypeToString, 0, false);
 
     // Install the @@hasInstance function.
     Handle<JSFunction> has_instance = InstallFunction(
         prototype, factory->has_instance_symbol(), JS_OBJECT_TYPE,
         JSObject::kHeaderSize, MaybeHandle<JSObject>(),
         Builtins::kFunctionPrototypeHasInstance,
@@ skipping 2619 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8